1. Field of the Invention
The present invention relates in general to circuits and methods for saving power on an integrated circuit and in particular to systems using the same.
2. Description of the Related Art
As new semiconductor fabrication techniques are developed, the number of gates which can be fabricated on a single integrated circuit chip continues to grow. As a result, more complex circuits which once required two or more chips to implement can now be provided as a single device. Present techniques allow for the fabrication of up to approximately fifty million gates per chip. By the year 2010, it has been estimated that the number of gates that can be fabricated on a single chip will approach one trillion or more.
Besides increased gate density, the maximum integrated circuit clock speeds also continue to increase with newer design and fabrication methods. Current integrated circuits operate in response to clock frequencies in the hundreds of megahertz. Within the next ten years however, clock frequencies of a gigahertz or more are expected to be common.
Higher gate densities and clock frequencies will allow the development of Systems-On-A-Chip (SoCs) in which processing circuitry, memory and input/output devices are all be fabricated together on a chip and distributed in a single package. For example, a microprocessor or microcontroller may be fabricated together with on-chip memory for storing the operating system and/or the basic input/output system (BIOS). The applications for SoCs are numerous, including portable personal computers, mobile personal communicators, and similar compact systems.
Increased gate densities and clock frequencies are not without drawbacks. Among other things, high-speed, high-density devices consume substantially more power. As a natural consequence, there can also be a substantial increase in heat dissipation. Thus, while high performance devices, like SoCs, are ideal for portable computers and telecommunications systems from the compactness point of view, the power consumption and heat dissipation problems must be carefully considered. This is especially true when addressing battery life and system packaging factors.
According to the principles of the present invention, an integrated circuit is disclosed which includes a plurality of circuit blocks for selectively performing data processing operations in response to a set of instructions. The integrated circuit further includes circuitry for dynamically powering xe2x80x9cupxe2x80x9d and xe2x80x9cdownxe2x80x9d selected ones of circuit blocks during the execution of the set of instructions.
Circuitry systems and methods embodying the principles of the present invention provide substantial advantages over the prior art. Among other things, power consumption and heat dissipation can be more precisely controlled and optimized since individual circuit blocks can be activated and deactivated. Moreover, since power control can be done in firmware and/or software, maximum flexibility is achieved. In other words, the user can customize the operation of the chip as required for a given application.